While mining out tiles in Possession, roof above freshly mined out tiles shows visual glitches as it appears to not remove the old connection to a wall that is no longer there. Exiting possession or claiming the tiles fixes any bugged tiles.

Steps for reproduction:

Turn up the gamma a bit, to make this easier to see

Start a new sandbox

Place a worker impass against one wall (to prevent other workers from claiming behind you)

Possess a worker

Mine out a new room without claiming the floor. The issue is most obvious at 3x3 or larger